(URGENT) Lemmy has an XSS vulnerability in the sidebar - eviltoast

cross-posted from: https://sh.itjust.works/post/923025

lemmy.world is a victim of an XSS attack right now and the hacker simply injected a JavaScript redirection into the sidebar.

It appears the Lemmy backend does not escape HTML in the main sidebar. Not sure if this is also true for community sidebars.

  • TruckBC@lemmy.caMEnglish
    6·
    1 year ago

    We have yet to confirm if a vulnerability exists in the sidebars that can be set by community mods.

    • Uncle@lemmy.caEnglish
      2·
      1 year ago

      can you temporally take away the ability for mods to put html or any kinda script into the sidebar, at least for now?

      • TruckBC@lemmy.caMEnglish
        3·
        1 year ago

        No. Unfortunately. This is not a confirmed vector of attack at this point but we are monitoring.

      • ChemicalRascal@kbin.social
        2·
        1 year ago

        That would essentially be patching the vulnerability. A temporary fix would be just preventing the sidebar from being editable.

        (Ideally the vulnerability would be patched, but these things take time.)

        • TruckBC@lemmy.caM
          5·
          1 year ago

          At this point it doesn’t seem like community sidebars have the voulnerabilty. We are fairly confident that they have identified the voulnerabilty and that lemmy.ca is safe as long as our admin accounts are properly locked down which we have confirmed.